1. Field of the Invention
This invention relates generally to Quality of Service (QoS) control for Virtual Private Network(s) (VPNs) established between smart phones and private networks (e.g., enterprise or agency intranet) over Long Term Evolution (LTE) commercial wireless networks. These VPN(s) may be used by smart phone applications to access data in the cloud in a secure manner and typically involve tunneling of original application IP packets in an encrypted fashion inside of an outer IP packet.
2. Background of Related Art
Verizon Wireless™ has recently become the first commercial service provider to fully launch a network with Long Term Evolution (LTE) 4G wireless broadband technology. Long Term Evolution (LTE) 4G wireless broadband technology is a recent technology that supports a fast and efficient all-Internet Protocol (IP) network (i.e., a network that provides services, e.g., voice, video, data, messaging, etc., solely over the Internet). It is expected that the majority of commercial service providers will also adopt an all-Internet Protocol (IP) network at some time in the near future.
As the future of technology gears toward an all-IP network, the number of available over-the-top (OTT) applications is expected to increase. An over-the-top (OTT) application is an application that uses a data channel provided by an Internet service provider (ISP) to connect to the Internet instead of using any special data handling features or network services offered thereby.
In accordance with conventional technology, over-the-top (OTT) application data is sometimes routed over a commercial wireless network via a virtual private network (VPN) tunnel (which involves the tunneling of original IP packets inside outer IP packets in an encrypted fashion). A virtual private network (VPN) tunnel provides additional transmission security to over-the-top (OTT) application data, which is especially helpful to over-the-top (OTT) applications that lack end-to-end encryption on their network connections.
Quality of service (QoS) refers to a set of performance characteristics by which a commercial wireless network is expected to convey data traffic to and from a client (quality of service (QoS) control mechanisms are applied to both the wireless and wireline components of a commercial network). Specific performance characteristics may include throughput (i.e. data quantity transmitted per unit time), latency (i.e. time delay between transmission and receipt of data), loss rate (i.e. frequency by which a commercial wireless network fails to deliver portions of transmitted data), jitter (i.e. a measure of variance of other characteristics), etc.
Currently, there exist several inherent limitations to the quality of service (QoS) treatment that a commercial wireless network is able to provide its' clients. For example, the maximum throughput that a commercial wireless network is able to provide across all clients is dependant on: a spectrum allocation held by the commercial wireless network, a backhaul infrastructure setup between cellular towers and fixed infrastructure within the commercial wireless network, the number of cellular towers in use within the commercial wireless network, the size of a footprint assigned to each cellular tower in use within the commercial wireless network, and any sources of electromagnetic interference within the commercial wireless network.
It is found that applications (e.g. smart phone applications) typically run better (i.e., perform more objective work per unit time and provide better user experience) when they are receiving a higher level of quality of service (QoS) treatment from a commercial wireless network as opposed to a lower level of quality of service (QoS) treatment. Consequently, many clients/service providers enter into contractual agreements with commercial wireless networks to ensure that they receive a data conveyance that is at-or-above a desired minimum performance level. For example, a commercial wireless network may agree (in exchange for monetary compensation) to provide a minimum of 12 kilobit/second throughput and a minimum of 0.1 second latency to a client user equipment (UE) that desires to receive real-time streaming video feed over that wireless network.
Commercial wireless networks use well-known internal techniques to ensure that contracted clients receive a pre-negotiated level of quality of service (QoS) treatment. For example, a network operator may delay transmitting data for one low-level quality of service (QoS) client to prioritize data transmission for another high-level quality of service (QoS) client. Likewise, a network operator may discard data packets transmitted to/from one low-level quality of service (QoS) client more frequently, to ensure data conveyance for another high-level quality of service (QoS) client.
Unfortunately, vendors of over-the-top (OTT) applications and associated data do not typically enter into contractual quality of service (QoS) agreements with commercial wireless networks (e.g. Long Term Evolution (LTE) networks). Therefore, over-the-top (OTT) applications are typically unable to benefit from quality of service (QoS) control mechanisms (e.g. priority, packet delay, guaranteed bit rate, etc.) available thereon. Instead, most over-the-top (OTT) applications (e.g., Skype, Netflix, etc.) provide services on a best-effort basis (i.e., data delivery, efficiency not guaranteed).
Differentiated Services (DiffServ) has defined a mechanism for classifying and managing network traffic on modern Internet Protocol (IP) networks, for the purposes of providing quality of service (QoS) treatment thereon. In particular, DiffServ uses a 6 bit field (i.e. a DS field) in an IP header for packet classification purposes.
In accordance with conventional DiffServ technology, a DS field may be influenced (set) by an application generating IP packets. Moreover, a virtual private network (VPN) client may copy a DiffServ header from an incoming application IP packet (that will eventually be encapsulated) to an IP header of a tunneling IP packet to extend DiffServ quality of service (QoS) treatment to a virtual private network (VPN) environment.
However, though smart phone applications, application cores in the cloud, and virtual private network (VPN) software may all influence the setting of a DS field, there is no guarantee that an Internet Protocol (IP) network (e.g. a long term evolution (LTE) network) will honor a DS field setting and provide desired quality of service (QoS) treatment, being that: first, the honoring of a DS field is not mandated by current standards and, second, triggering quality of service (QoS) treatment in such a fashion defeats the purpose of quality of service (QoS) control as, conceivably, all types of data traffic flowing through an IP network could be marked for preferential treatment by a source application.
As commercial wireless networks begin carrying data for over-the-top (OTT) mission critical applications, such as applications used by emergency dispatch personnel and emergency first responders, a best-effort treatment of over-the-top (OTT) applications will no longer be acceptable. This is especially true in times of disaster, when networks are likely heavily congested. Hence, a successful means of extending quality of service (QoS) treatment to over-the-top (OTT) applications, including over-the-top (OTT) applications transmitting data over a virtual private network (VPN) tunnel, is needed.